How do I resolve a variable in a subshell inside of "bash -c"?
In the following, the second subshell -- the one with an "echo" inside -- resolves correctly. The first subshell -- with "touch" -- does not.
/bin/bash -c "\
A=/tmp/foo; \
echo $( touch \$A; ); \
echo $( echo in subshell, \$A; ); \
"
It is simply, because the subshell is evaluated from your current shell and not from your subshell. Escaping the $() will make it work as you expected:
/bin/bash -c "\
A=/tmp/foo; \
echo \$( touch \$A; ); \
echo \$( echo in subshell, \$A; ); \
"
Because you are using double quotes, Bash is evaluating the whole string first, then executes it.
Replace your first line with /bin/bash -c echo “\ and you will see the following is the code bash -c is attempting to execute.
/bin/bash -c echo "\
…
touch \$A; ); echo $( echo in subshell, \$A; ); "
echo in subshell, \$A; ); "
touch \$A; ); echo $( echo in subshell, \$A; );
touch \$A;
echo in subshell, \$A; );
echo in subshell, \$A;
Use single quotes instead.
... in your explanation.